1. From the Singapore National Eye Center,
2. Biostatistics Unit, Faculty of Medicine, and the
3. Glaucoma Research Unit, Moorfields Eye Hospital, London, United Kingdom; and the
4. From the Singapore National Eye Center,5Departments of Ophthalmology and4Singapore Eye Research Institute, Singapore.
5. Departments of Ophthalmology and6Community, Occupational and Family Medicine, National University of Singapore, Singapore; the4Singapore Eye Research Institute, Singapore.